On 1/9/19 11:39 AM, Russel Winder wrote:
On Tue, 2019-01-08 at 09:59 -0500, Steven Schveighoffer via Digitalmars-d-
learn wrote:
[…]
Russel, make sure your destructor both checks whether the underlying
resource is set, and clears it to invalid when freeing it.
Even types that can't be copied can be moved, or temporarily created as
rvalues. When they are moved the shell they get moved out of is still
destructed! So it has to have a state where it can be destroyed, even
though there is no resource.
I have added tests in the destructor but given the constructor should throw an
exception on a failure to initialise the internal state correctly, it really
ought to be unnecessary. but I guess it cant hurt being there!
The point is that some libraries are not robust enough to handle freeing
data multiple times. And with the way postblit/dtors work, you have to
handle this properly in D.
As I noted to Nicholas it seems the application is getting a valid data
structure returned with invalid data and that is where the SIGSEGV is. This is
really weird as I have just finished a Rust version of the same application
and it works fine. And this D version used to work fine. It is a real mystery
why there is a problem now.
Hm... your description of having the problem happen at the end of main
seems to suggest it has something to do with destruction.
-Steve
